Primer

ABSTRACT

A percussion primer for small caliber ammunition in which the pellet loading can be accomplished by disc punching machines to increase primer production rates. A thin sheet of plastic material is seated in the base portion of the primer cup and has an upper surface coated with an abrasive material, preferably antimony sulfide. A plastic disc of igniter material overlies the abrasive material, and a plastic disc of high energy combustible material overlies the igniter disc. A protective foil overlies the combustible disc, and an anvil is seated in the cup and pressed against the foil.

United States Patent [1 1 White et al.

[ Nov. 13, 1973 [22] Filed:

[ PRIMER [75 Inventors: Wilmer White, Haddonfield, N.J.;

Thomas Q. Ciccone, Cornwells, Pa.

[73] Assignee: The United States of America as represented by theSecretary of the my Sept. 28, 1972 [21] Appl. No.: 293,192

[52] US. Cl. 102/45 [51] Int. Cl. F42!) 19/10 [58] Field of Search102/45, 38, 86.5

[56] I References Cited UNITED STATES PATENTS 2,021,498 11/1935 Campbell102/45 3,320,887 5/1967 Quinlan et al. 102/45 Primary Examiner-Robert F.Stahl Att0rney-Harry M. Saragovitz et a1.

[57] ABSTRACT 4 Claims, 1 DrawingFigure PATENTEB NOV 1 3 I975 PRIMERThis invention described herein may be manufactured, used, and licensedby or for the Government for governmental purposes without the paymentto us of any royalty thereon.

'This invention relates to primers, and more particularly, to percussionprimers for small caliber ammunition.

l-leretofore, a loosely bound mix of chemical ingredients for a primerpellet were mixed and pelleted by manually rubbing the mix overperforated plates of predetermined dimensions prior to loading with aknock out plate.

It is an object of the invention to provide a primer having a laminatedplastic pellet.

Another object of the invention is to provide such a primer that enablesa high volume production rate to be obtained with product uniformity.

These and other objects, features and advantages will become moreapparent from the following description and accompanying drawing whichis a sectional view of a percussion primer embodying the principles ofthe invention.

The substantially cylindrical brass cup 11 has a closed base portion 12of predetermined thickness to accommodate penetration by a firing pin ofa munition firing mechanism (not shown). The laminated primer pellet,shown generally at 13, preferably includes a thin sheet 14 of plasticmaterial having a lower or bottom surface that seats against the cupbase portion 12 as well as an upper surface that is coated with anabrasive material 15. A plastic disc 16 of igniter material overlies theabrasive coating 15, and a plastic disc 17 of high energy combustiblematerial overlies the igniter disc 16. A waterproof seal of protectivefoil 18 overlies the combustible disc 17, and the conically shaped brassanvil 19 is press-fitted within the sidewalls of cup 11 with the anvilnose portion 20 pressed against the foil 18.

Preferably, the abrasive coated thin plastic sheet 14 comprises a thinlayer of cellulose nitrate base sealing compound having a bottom surfacethat adhers to the cup base 12 and an upper surface which is coated withantimony sulfide 15. The igniter plastic material 16 is prepared insheet form and consists of a polymerized mixture of nitrocellulose,acetone, lead styphnate and tetracene. The highly combustible plasticmaterial 17 is prepared in sheet form and consists of a polymerized fueland oxidizer mixture of nitrocellulose, acetone and barium nitrate. Anappropriate disc punching machine punches the desired igniter plasticdisc 16 of predetermined size from the igniter sheet and the disc 16 isallowed to fall directly into its cup 11 upon the abrasive coated sheet14. Similar punching; technique is utilized for loading one or morehighly combustible discs 17 from its sheet, prior to assembling apunched aluminum protective foil 18 which also can be of wax paper ortin material. After being loaded, the primer cup is drained and driedprior to insertion of anvil 19. Upon drying of the primer, substantiallyall of the acetone will have been evaporated.

Various modifications, changes or alterations may be resorted to withoutdeparting from the scope of the invention as defined in the appendedclaims.

We claim:

1. A percussion primer for small caliber ammunition, comprising asubstantially cylindrical cup member having a closed base portion,

a thin sheet of plastic material having a bottom surface seated againstsaid base portion and an upper surface coated with an abrasive material,

a plastic disc of igniter material overlying said abrasive material,

a plastic discof high energy combustible material overlying said igniterdisc,

a protective foil overlying said combustible disc, and

an anvil seated in said cup member and pressed against said foil.

2. The structure in accordance with claim 1 wherein said abrasivematerial is antimony sulfide.

3. The structure of claim 2 wherein said igniter material includesnitrocellulose, lead styphnate and tetracene, and said combustible discincludes nitrocellulose and barium nitrate.

4. The structure of claim 3 wherein said foil is a material selectedfrom the group including aluminum, tin

and wax paper.

2. The structure in accordance with claim 1 wherein said abrasivematerial is antimony sulfide.
 3. The structure of claim 2 wherein saidigniter material includes nitrocellulose, lead styphnate and tetracene,and said combustible disc includes nitrocellulose and barium nitrate. 4.The structure of claim 3 wherein said foil is a material selected fromthe group including aluminum, tin and wax paper.